Ford has produced some of the most powerful engines to ever come
out of Detroit. With the V8 engine sizes ranging from 221-460, there is an
engine size and configuration to cover just about any need or application.
Ford engines do have some unique characteristics not found in any other
make, so in this section we will try to familiarize you with some of the
more common differences. This valve train related information should
help you when choosing parts or assembling your engine.

Engine Types

Small Block, Uses "31" and "35" Prefix This is the standard engine in most V8 applications. It has been around
since the early 1960’s and remains very popular today in many
configurations. The Small Block Ford engine is commonly referred to as
the 5.0 engine found in the Mustang for many years. This engine has
become one of the most frequently modified engines Ford has ever
produced. There are a few differences in the valve train of this design, but
for the most part, they are the same. One thing to remember is that the
221-302 engines have a very short deck height, requiring a short
pushrod. The 351W engine, on the other hand, has a tall deck and a
longer pushrod. The 1985-1995 5.0 blocks differ from the earlier blocks
in that the lifter bosses are taller to accommodate the hydraulic roller
lifters. The base circles of the cams for these blocks are larger because
of the higher position of the lifters. These engines use either a prefix “31”
(302) or a “35” (351) camshaft, depending on the firing order.

SVO V8 Race Engine, Uses “35” Prefix This engine is almost always found in all out racing, and is a cross
between the Windsor and Cleveland designs. It utilizes a Windsor type
block and a Cleveland type head. The newest of the head designs is
referred to as the “Yates” head.

Cleveland/Modified, Uses “32” Prefix
This design was introduced in 1969 and was available as a 351
Cleveland, a 351C Boss or a 351/400 Modified. The easiest way to tell
these engines from the standard small block is by looking at the front
covers. The small block / SVO engines have a cast aluminum front cover
and water pump housing. The Cleveland/Modified engines have a
stamped steel flat front cover. Other than a few rocker arm differences,
the valve train in all of these engines is very similar.

Big Block “FE”, Uses “33” Prefix
Ford’s “FE” engine family was introduced in 1958 and was available
as either a 332 or a 352 version. Later, the range was expanded to
include 390-428 versions. They have been out of production since the
mid seventies but remain popular today. These engines utilize a shaft
rocker arm system and can be most easily recognized by the fact that
the intake manifold is very wide and extends part way under the valve
covers. Almost all of the parts in the “FE” series are used only in this
engine and are not interchangeable with other engine families.

Big Block “FF”, Uses “34” Prefix
The engine commonly referred to as the Ford Big Block is the 429-460
and was used in light trucks and motorhomes. It is an outstanding engine
for boats, bracket racing or towing. It typically has a similar but larger
“Cleveland” style valve train.

Modular Type Engines
The Ford “Modular Engine” was introduced in the early 1990’s, with the
idea of designing a new generation of engines from scratch, rather than
basing them on then-current production engines. They were developed to
replace all existing Ford V8 pushrod engines. The “Modular” term came
about because of the many interchangeable components between the
SOHC and DOHC engines, as well as the ability of Ford to machine and
assemble the various engines on the same assembly lines.

The design focuses on low friction, excellent sealing and increased
block stiffness. With a modern block and head design in 2 valve, 3 valve,
and 4 valve configurations, the engines are both versatile and powerful.
They have a sophisticated overhead cam design in both single and dual
overhead cam versions that utilizes a roller finger follower to reduce
friction, increase rpm potential and eliminate maintenance.

All of the cylinder blocks have deep skirts, and nearly all of the main
caps are cross-bolted. SOHC engines have cast iron blocks; DOHC
engines have aluminum blocks. All cylinder heads are aluminum, with
very long head bolts to reduce distortion of the cylinder bores and improve
sealing. The new design also allows the accessories to be rigidly mounted
directly to the block.

4.6L & 5.4L 2 Valve SOHC, Uses “102” Prefix The 4.6L version of this engine first came out in the 1991 Lincoln Town
Car and later was installed in the Crown Victoria, Grand Marquis,
Thunderbird and Cougar. This engine has grown to become the popular
5.0 Mustang replacement.

In 1997 the 5.4L version of the 2 valve SOHC engine was introduced.
This engine, known as the "Triton" truck engine, has numerous parts that
are interchangeable with the modular car engines. However, not all are
identical since the truck engines are built to handle more severe duty.

4.6L & 5.4L 3 Valve SOHC, Uses “127” Prefix
The 4.6L SOHC 3 valve engine is available in today’s Mustangs. The
engine features variable cam timing, allowing the valves to open and
close earlier or later as needed for optimum power.

This technology was first introduced in 2004 in the 5.4L 3 valve DOHC
engines. This engine, also known as the "Triton", is primarily in the
F-150 trucks.

4.6L 4 Valve DOHC, Uses “106” Prefix
This engine showed up first in the 1993 Lincoln Mark VIII and later in
the front-wheel drive Continental. It has since been put in performance
cars, such as the Mustang Cobra.